Shapes Area Calculator
Calculate irregular and complex area shapes using rectangles, rectangle borders, circles, rings, triangles (base/height or sides), trapezoids, sectors, and parallelograms. Perfect for roofing, landscaping, decks, and custom construction projects.
All Units
Square Feet
0sq ft
Square Inches
0sq in
Square Yards
0sq yd
Square Meters
0sq m
Square Centimeters
0sq cm
Acres
0acres
How to Calculate Square Footage
Learn the fundamentals of measuring area in square feet
Square footage is a measurement of area in square feet (sq ft). It's essential for flooring, painting, roofing, landscaping, and construction projects.
Step-by-Step Guide:
Measure the length
Measure the length of the area in feet. For greater accuracy, include inches (e.g., 12 ft 6 in = 12.5 ft).
Measure the width
Measure the width of the area in feet.
Multiply length × width
Multiply the length by the width to get square footage.
Irregular shapes
Break the area into rectangles, triangles, or circles, calculate each separately, then add them together.
Common Formulas:
Rectangle
Length × Width
Circle
π × Radius²
Triangle
(Base × Height) ÷ 2
Trapezoid
((Top + Bottom) × Height) ÷ 2
Area Unit Conversions
Convert between square feet, square meters, acres, and other area units
| From | To | Multiply by |
|---|---|---|
| 1 sq ft | sq in | 144 |
| 1 sq ft | sq m | 0.0929 |
| 1 sq ft | sq yd | 0.1111 |
| 1 sq m | sq ft | 10.7639 |
| 1 acre | sq ft | 43,560 |
| 1 acre | sq m | 4,047 |
Common Uses for Square Footage Calculations
Practical applications for square footage measurements in home improvement and construction
Flooring & Tile
Calculate how much flooring material you need. Add 10% waste factor for cuts and mistakes.
Paint & Wallpaper
Measure wall area and subtract windows/doors. One gallon covers ~350-400 sq ft.
Roofing
Calculate roof surface area for shingles. Roofing is sold in "squares" (100 sq ft each).
Landscaping
Calculate lawn area for sod, seed, or fertilizer. Measure irregular areas using shapes.
Real Estate
Calculate home square footage using ANSI Z765 guidelines. Include living spaces, exclude garages.
Carpet & Rugs
Carpet is typically sold by square yards. Divide sq ft by 9 to convert to sq yd.
Pro Tips for Accurate Measurements
Best practices to ensure precise measurements and avoid costly mistakes
Measure twice, order once
Always double-check measurements before purchasing materials.
Add waste factor
Include 10-15% extra for cuts, pattern matching, and future repairs.
Use feet and inches
Converting to decimal feet (e.g., 6 in = 0.5 ft) gives more accurate results.
Break down irregular shapes
Divide complex areas into simple rectangles, triangles, and circles.
Subtract openings for walls
Don't forget to subtract windows and doors when calculating paint or wallpaper.
Frequently Asked Questions
Common questions about square footage calculations and area measurements